Circuit controlling device



Jan. 4, 1938. c. w. KUHN CIRCUIT CONTROLLING DEVICE Filed NOV. 26, 1934la IHHIHIH; 15

5 ,e4 lxj 1,6 11 11 16 I' O o 36 o O o o Patented Jan. 4, 193s 2,104,399CIRCUIT Con'rnoLLiNG DEVICE Clarence W. Kuhn, Milwaukee, Wis., assignerto Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of DelawareApplication November 26, 1934, SerialV No. 754,749

7 Claims.

This invention relates to circuit controlling devices, and while notlimited thereto is particularly applicable to starting relays for splitphase motors.

A relay embodying certain features of the present invention is disclosedin my copending application Serial No. 514,363, filed February 9, 1931,which became Patent No. 1,988,848 on January 22, 1935 and the presentapplication is lo a continuation of the aforesaid application as to allcommon subject matter.

As is well known, split phase motors are provided with a running windingand a starting winding and it is the usual practice to effect control ofthe latter winding by means of a relay which is responsive to currentconditions in the running winding. Small split phase motors are commonlyemployed in electric refrigerators of the household type and in suchinstallations difculty has heretofore been encountered in providing astarting relay which is of the required sensitiveness and which operateswithout objectionable noise.

It is an object of the present invention to provide a low cost startingrelay which is exceedingly sensitive and quiet in operation and which isparticularly adapted for use in connection with electric refrigeratorsof the household type.

Another object is to provide a relay of the aforesaid character havingimproved adjusting means associated therewith.

Various other objects and advantages of the invention will hereinafterappear.

'I'he accompanying drawing illustrates certain embodiments of theinvention which will now be described, it being understood that theembodiments illustrated are susceptible of modification withoutdeparting from the spirit and scope of the appended claims.

In the drawing,

Figure 1 is a front elevational view of a starting relay embodying theinvention;

Fig. 2 is a sectional view taken on line 2--2 of Fig. 1;

Fig. 3 is a plan view of the relay shown in Fig. 1;

Fig. 4 is a plan View of the relay shown in Fig. 1 illustrating amodified contact and terminal arrangement therefor;

Fig. 5 is a sectional view on line 5-5 of Fig. 4;

Figs. 6 and 7 are diagrammatic views illustrating the circuitconnections for the relays shown in Figs. 3 and 4;

Fig. 8 is a vertical sectional view of a modified form of relayembodying the invention, and

CTI

(Cl. 20G-111) Fig. 9 is a view in the operated position of a part of themodified form of Fig. 8.

The relay illustrated in Figs. 1 and 2 is provided with an elongatedspring contact I0 arranged upon the upper face of an insulating 5 plateII and having one end thereof secured to said plate, between theinsulated washers I2 and I3, by a bolt i4. Plate II is xed to asupporting bracket I5 by screws I6 and said plate carries a solenoidwinding I I having a plunger 10 I8 associated therewith which isoperatively connected to the free end of spring contact I0.

Winding I'I is Wound upon an insulating spool I9 having a center openingtherein for receiving plunger I8, and said spoolis secured to a magl5netic washer 20 which is fixed to the under side of insulating plate IIby screws 2| shown in Fig, 3. insulating spool I9 is secured to washer20 by a plug 22 which is threaded into said washer and is provided withan enlarged head 20 23 for engaging a shoulder formed on the upper endof said spool within the `opening therein. The lower end of plunger I8is weighted by a projecting nange 24` and said plunger has an insulatingpin 25 mounted upon the upper end 25 thereof which is guided within anopening in plug 22 and extends upwardly through an opening in insulatingplate II. The free end of spring contact I0 is provided with an openingfor receiving pin 25 and the upper end of said 30 pin has an insulatingwasher 26 mounted thereon for engaging the upper face of said springcontact.

Spring Contact I0 is normally held in the position shown in Fig. 2 bythe weighted plunger 35 I8 and said contact is biasedto move upwardlyupon upward movement of said plunger into its attracted position. Tominimize noise upon movement of plunger I 8 into its attracted positionthe same has cushioning means associated 40 therewith comprising aplurality of relatively thin fabric washers 28 and a soft rubber washer29 which are mounted upon the upper face of flange 24. The fabricwashers 28 are preferably located between washer 29 and flange 24 and 45upon attraction of plunger I8 washer 29 abuts the lower face of spool I9to prevent sealing of the upper end of said plunger with the face ofplug 22. Obviously the washers 28 and 29 act as a cushion to minimizenoise upon movement 50 of plunger I8 into its attracted position. Alsoit should be noted that the number of fabric washers 28 may be varied toadjust the air gap between the upper end of plunger I8 and plug 20 andthereby provide for dropping out of the 55 plunger at a selected currentvalue in the solenoid winding i1.

The relay is also provided with means for adjusting the value of currentin solenoid winding il which is required to effect movement of plungeri8 into its attracted position. For this purpose washer 26 is looselymounted upon pin 25 and a plurality of relatively thin shim washers 30are arranged between the upper face of washer I6 and a Cotter pin 3isecured to the upper end of said pin. As is apparent, by varying thenumber of shim washers 3U the normal air gap between plunger i8 and plug22 may be varied to adjust the current value at which said plungerresponds.

The above described relay may be used in starting systems or varioustypes, as for example those shown in Figs. 6 and '7. For a startingsystem of the type shown in Fig. 6 the relay has a resistance element 33secured to the bracket il by a bolt 34 and insulating plate il isprovided with 'the Contact terminal arrangement shown in Fig. 3. For thestarting system shown in Fig. 7 the resistance element 33 is omitted andinsulatr ing plate il of the relay is provided with the contact andterminal arrangement shown in Fig. 4.

In the embodiment shown in Fig. 3 insulating plate il has a stationarycontact 35 xed to the upper face thereof to be engaged by spring contactIO upon upward movement thereof from the normal position shown in Fig. land said plate also has a plurality of terminal plates 36, 3l and 38mounted upon the upper face thereof. Terminal plate 36 is electricallyconnected to the inner end of spring contact i0. Resistance element 33is connected between terminal plates 36 and 31 and the solenoid windingil of the relay is connected between stationary contact 35 and terminalplate 38.

The relay shown in Fig. 3 is connected as shown in Fig. 6 to controlstarting of a single phase alternating current motor M having a runningwinding R and a starting winding S. The supply circuit for the motor isindicated by lines Ll, L2 and a switch 39 is shown for establishingpower connections for the motor, it being understood that such switchmay be of any desired type, as for example a temperature controlledswitch of an electric refrigerator. Upon closure of switch 39 circuit isestablished from line L2 to stationary contact 35 of the starting relay,and thence through the solenoid winding Il of said relay and the runningwinding R of the motor to line L1. The inrush of current through therunning winding R causes immediate response of the relay and thestarting Winding S is then energized by a circuit extending from line L2to stationary contact 35, through spring contact i to terminal 36,through resistance element 33 to terminal 31, and thence through thestarting winding S to line L1. As the speed of the motor increases thecurrent in the solenoid winding I1 decreases in value and when the motoris brought up to its running speed plunger I8 drops out to return springcontact l0 to open position. The circuit for the starting winding S isthus interrupted and the running winding remains energized for continuedoperation of the motor.

In the embodiment illustrated in Fig. 4 the insulating plate l i hasterminal plates 40 and 4| mounted upon the upper face thereof. Theterminal plate I0 is electrically connected to the inner end of springcontact i0 and the operating winding il of the relay is connectedbetween the terminal plates 40 and Il. Also a stationary contact 3l isprovided for engagement by spring contact Il upon response of the relayand an additional stationary contact 42 is provided to be engaged bysaid spring contact when the relay is in normal position.

'I'he relay shown in Fig. 4 isconnected as shown in Fig. 7 to eii'ectstarting of motor M through the medium of an autotransrormer winding 43and a condenser u, said transformer winding being connected in serieswith the starting winding S of the motor and said condenser beingconnected in-shunt with said autotransformer winding. The left'handterminals of starting winding S and running winding R of the motor arepermanently connected to line Ll and upon closure of switch 33 circuitis established from line L to terminal plate 4l through winding I1 ofthe starting relay to the right hand terminal of the running winding R.The inrush of current through the running winding R causes immediateresponse of the relay and spring contact Il then engages stationarycontact 3l to connect terminal T1 of the autotransi'ormer winding 43 toline L. 'I'he motor is then adapted to accelerate and when the same isbrought up to running speed the current in winding l1 of the relay isreduced to a value which permits return of the relay to normal position.Terminal 'I'l of the autotransformer winding is then disconnected fromline I..2 and the terminal 'I'2 of said winding is connected throughstationary contact l! and spring contact i3 to line I..z for running.

Referring now to Figs. 8 and 9, the same illustrate a modification ofthe relay shown in Fig. l1. The relay shown in Fig. 8 is provided withan insulating plate 45 having a movable contact l( mounted upon theupper face thereof. The rear end of contact II is fulcrumed upon aproiection 4T on the upper face of plate 4l and is provided with anopening for receiving a screw Il fixed to said plate. The iront end oi'-contact 4l is biased to move upwardly from the position shown in Fig. 8into the position shown in Fig. 9 by a spring 49 which is held undercompression between the upper face of said contact and a nut Bil on theupper end of screw Il.

Contact I6 is provided with an operating solenoid which is similar tothat employed in the relay hereinbefore described. However, the plungerIl is provided with a soft felt washer instead of a rubber washer 2l andthe insulating spool Il for winding i1 is directly secured to the underside of plate Il" by the plug 22 which is screwed within a threadedopening in said plate. A metal pin l2 is iixed to the upper end ofplunger Il and said pin is guided within the opening in plug 22 by aninsulating washer 53 mounted upon said plug. Pin l2 extends upwardlythrough an opening in contact 4|, said opening having a shoulderedinsulating washer 54 mounted therein for guiding said pin and forpreventing engagement thereof withsaid contact. The upper end of pin IIhas an. insulating washer 55 mounted thereon which is held in place by anut 5I and said pin has a coil spring I1 associated therewith which isarranged between said nut and the insulating washer u on contact 43.

As shown in Fig. 8. plunger il normally acts bygravity to hold theinsulating washer Il thereon in engagement with the washer I4 on'movable contact 4l against the action of vspring I1 and to also hold thecontact in the position shown in this figure against the action ofspring 43. Upon movement of plunger Il into its attracted position thepin i2 moves upwardly with respect to contact I6 to permit expansion ofspring 51 and to also permit contact 46 to move upwardlyinto theposition shown in Fig. 9 under the action of spring 49. In connectionwith the foregoing it should be noted that the felt washer 5l acts as acushion to minimize noise incident to movement `of the plunger into itsattracted position. Also it should be noted that upon dropping out ofthe plunger spring 5l is compressed and the same thus acts as a cushionto minimize noise incident to return of said plunger and contact 4B tonormal position.

What yI claim as new and desire to secure by Letters Patent is:

1. In a. starting relay for alternating current motors, in combination,an insulating support comprising a horizontally arranged body portionhaving an associated vertically arranged spool on the under sidethereof, cooperating stationary and movable contacts mounted upon theupper side of said body portion, said movable contact being movablebetween given extreme positions, a'winding carried by said spool, aplunger for said winding movable vertically within an opening in saidspool, said plunger having an enlarged weight projection on the lowerend thereof and being suspended from said movable contact to normallyhold the latter in one extreme position, means for moving said movablecontact into its other extreme position prior to full movement of saidplunger into a given attracted position, said plunger being movable withrespect to said contact to permit full movement thereof into itsattracted position and a plurality of removable shims associated withsaid plunger and arranged between the weight projection on the lower endthereof and the lower end of said spool, said shims providing foradjustment of the attracted position of said plunger.

2. In a starting relay for alternating current motors, in combination,an insulating support comprising a horizontally arranged body portionhaving an associated vertically arranged spool on the under sidethereof, cooperating stationary and movable contacts mounted upon theupper side of said body portion, said movable contact' being movablebetween given extreme positions, a winding mounted upon said spool, aplunger for said winding movable vertically within an opening in saidspool, said plunger having an enlarged Weight projection on the lowerend thereof and being suspended from said movable contact to normallyhold the latter in one extreme position, means for moving said contactinto its other extreme position prior to full movement of said plungerinto a given attracted position, said plunger being movable with respectto said contact to permit full' movement thereof into its attractedposition and a yielding member and a plurality of relatively thinremovable shims associated with said plunger and arranged between theweight projection on the lower end thereof and the lower end of saidspool, said yielding member serving as acushioning stop for said plungerupon attraction thereof and said shims providing for adjustment of theattracted position of said plunger.

3. In an electromagnetic relay, in combination, a movable contact, anoperating solenoid therefor, having a fixed winding and a movableplunger, said plunger being suspended from said contact and acting bygravity to hold said contact in a given extreme position, said plungerbeing also normally positioned with respect to said winding to renderthe normal magnetic pull thereon of'relatively low value, spring meansfor moving said contact into an opposite extreme position and alsotending to move said plunger out of normal position to thereby reducethe current value required to move said plunger out of such position,said contact being movable under the action of said spring means intoits last mentioned extreme position prior to full movement of saidplunger into its attracted position, a lost motion operating connectionbetween said plunger find said contact permitting full movement of saidplunger into its attracted position upon arrest of said contact in itslast mentioned extreme position and cushioning means associated withsaid plunger for arresting the same in its attracted position.

4. In an electromagnetic relay, in combination, a. movable contact, anoperating solenoid therefor, having a fixed winding and a movableplunger, said plunger being suspended from said contact and acting bygravity to hold said contact in a given extreme position, said plungerbeing also normally positioned with respect to said winding to renderthe normal magnetic pull thereon of relatively low value, spring meansfor moving said contact into an opposite extreme position and alsotending to move said plunger out of normal position to thereby reducethe current value required to move. said plunger out of such position,said contact being movable under the action of said spring means intoits last mentioned extreme position prior to full movement of saidplunger into its attracted position, a 10st motion operating connectionbetween said plunger and said contact permitting full movement of saidplunger into its attracted position upon arrest of said contact in itslast mentioned extreme position and adjusting means associated with saidplunger for varying the normal and attracted positions thereof. l

5. In an electromagnetic relay, in combination, a movable contact, afixed insulating spool having a solenoid winding mounted thereon, avertically arranged solid cylindrical plunger movable within an openingin said spool and having an enlarged weight projection on the lower endthereof, said plunger being suspended from said contact and acting bygravity to hold said contact in a given extreme position, said plungerbeing also normally positioned with respect to said winding to renderthe normal magnetic pull thereon of relatively low value, spring meansfor moving said contact into an opposite extreme position and alsotending to move said plunger out of normal position to thereby reducethe current value required to move said plunger out of such position,said contact being movable under the action of said spring means intoits last mentioned extreme position prior to full movement of saidplunger into its attracted position and a lost motion operatingconnection between said plunger and said contact permitting fullmovement of said plunger into its attracted position upon arrest of saidcontact in its last mentioned extreme position.

6. In an electromagnetic relay, in combination, a switch including amovable contact, a fixed insulating spool having a solenoid windingmounted thereon, a vertically arranged plunger movable within an openingin said spool and having a weight projection on the lower end thereof,said plunger being suspended from said contact and acting by gravity tohold said contact in a given extreme position, said plunger being alsonormally positioned with respect to said winding to render the normalmagnetic pull thereon of relatively low value, spring means for movingsaid contact into an opposite extreme position and also tending to movesaid plunger out oi normal position to thereby reduce the current valuerequired to move said plunger out of such position, said contact beingmovable underthe action of said spring means into its last mentionedextreme position prior to full movement of said plunger into itsattracted position, a lost motion operating connection between saidplunger and said contact permitting full movement of said plunger intoits attracted position upon arrest of said contact in its last mentionedextreme position, and a cushioning member located between the lower endof said spool and the weight projection on said plunger for arrestingsaid plunger in its attracted position.

7. In an electromagnetic relay, in combination, a horizontal insulatingbase, a switch mounted on the upper side of said base and including amovable Contact, an insulating spool fixed to the under side of saidbase and having a solenoid winding mounted thereon, a verticallyarranged plunger movable within an opening in said spool and having anenlarged weight projection on the lower end thereof, said plunger beingsuspended from said contact and acting by gravity to hold said contactin a given extreme position, said plunger being also normally positionedwith respect to said winding to render the normal magnetic pull thereonoi' relatively low value, spring means associated with said contact formoving the same into an opposite extreme position and also tending tomove said plunger out of normal position to thereby reduce the currentvalue required to move said plunger out of such position, said movablecontact being movable under the action of said spring means into itslast mentioned extreme position prior to i'ull movement of said plungerinto its attracted position, a. lost motion operating connection betweensaid plunger and said contact permitting full movement of said plungerinto its attracted position upon arrest of said contact in its lastmentioned extreme position, and a cushioning member located between thelower end of said spool and the weight projection on said plunger forarresting said plunger in its attracted position.

CLARENCE W. KUHN.

